针对低阻球状异常体的多偏移距磁偶源瞬变电磁法全期视电阻率计算研究

Study of multi-offset magnetic dipole source transient electromagnetic method all time apparent resistivity calculation for low resistance spheroidal anomaly

本文针对浅层球状低阻异常体模型,使用二分法的最优化计算方法求解多偏移距的瞬变电磁法的全期视电阻率,分析不同偏移距下对模型中球状异常体的识别能力。发现对于浅层异常体探测问题,在偏移距接近球状异常体大小的情况下,能够确定异常体的水平距离和深度。当偏移距远大于球状异常体大小时,则不能确定异常体位置。

Aiming at the shallow spherical low resistance abnormal body model,the optimal calculation method of dichotomy is used to solve the whole time apparent resistivity of multi-offset transient electromagnetic method,and the identification ability of spherical abnormal body in the model under different offset is analyzed.It is found that the horizontal distance and depth of the anomalous body can be determined when the offset is close to the size of the spherical anomalous body.When the offset is much larger than the size of spherical anomaly,the anomaly location cannot be determined.